Now showing items 1-18 of 18

  • Battery aging impedance spectroscopy and incremental capacity analysis 

    Ovejas Benedicto, Victòria Júlia; Cuadras Tomàs, Àngel (ZAHNER-elektrik GmbH & Co. KG, 2017)
    Conference report
    Open Access
    We analize electrochemical LiFePO4 cells with impedance spectroscopy and incremental capacity analysis in order to establish a correlation with capacity fade. We found that polarization and diffusion impeances increased ...
  • Battery Impedance Spectroscopy obtained from Electrochemical Model 

    Miró Jané, Pol; Cuadras Tomàs, Àngel (2017)
    Conference report
    Open Access
    We investigate impedance spectra obtained from an electrochemical model using pulsed signals. We characterize the dependence of NiMH battery parameters such as electrodes porosity and conductivity on impedance. We are able ...
  • Battery state of charge determination from heat and entropy measurements 

    Ovejas Benedicto, Victòria Júlia; Cuadras Tomàs, Àngel (2012)
    Conference lecture
    Restricted access - publisher's policy
  • Battery state of charge determination from phase measurements 

    Cuadras Tomàs, Àngel (2012)
    Conference lecture
    Restricted access - author's decision
  • Desarrollo de un sistema de recuperación de amoníaco de purines de cerdo mediante evaporación al vacío 

    Estefano, Roberto; Cuadras Tomàs, Àngel; Flotats Ripoll, Xavier (2018)
    Conference lecture
    Open Access
  • Determination of a System’s Entropy Using Pyroelectric Sensors 

    Cuadras Tomàs, Àngel; Ovejas Benedicto, Victòria Júlia (2015-12)
    Article
    Open Access
    We propose a system for measuring entropy variations, S, in thermal systems using pyroelectric sensors. These sensors convert time-dependent temperature variations into electrical current. Consequently, heat and ...
  • Entropy as a wear out indicator: The resistor example 

    Cuadras Tomàs, Àngel; Ovejas Benedicto, Victòria Júlia; Quílez Figuerola, Marcos (2013)
    Conference report
    Restricted access - publisher's policy
    In this contribution we aim at proposing entropy measurements in resistive elements to characterize the induced damage due to current and Joule effect dissipation. 0.25 W off the shelf resistors are biased with constant ...
  • Entropy characterisation of overstressed capacitors for lifetime prediction 

    Cuadras Tomàs, Àngel; Romero, Ramón; Ovejas Benedicto, Victòria Júlia (2016-12-30)
    Article
    Open Access
    We propose a method to monitor the ageing and damage of capacitors based on their irreversible entropy generation rate. We overstressed several electrolytic capacitors in the range of 33 µF–100 µF and monitored their entropy ...
  • EVEA: espai virtual d'electrònica analògica 

    Cuadras Tomàs, Àngel; Hornero Ocaña, Gemma; Serrano Finetti, Roberto Ernesto; Gasulla Forner, Manuel (2006-02)
    Conference report
    Open Access
    El projecte Espai Virtual d’Electrònica Analògica (EVEA) constitueix un entorn virtual, accessible des d’internet, que integra els continguts d’electrònica analògica presents en diferents assignatures de la titulació ...
  • Impedance characterization of an LCO-NMC/graphite cell: ohmic conduction, SEI transport and charge-transfer phenomenon 

    Ovejas Benedicto, Victòria Júlia; Cuadras Tomàs, Àngel (Multidisciplinary Digital Publishing Institute (MDPI), 2018-09-10)
    Article
    Open Access
    Currently, Li-ion cells are the preferred candidates as energy sources for existing portable applications and for those being developed. Thus, a proper characterization of Li-ion cells is required to optimize their use and ...
  • Irreversible entropy model for damage diagnosis in resistors 

    Cuadras Tomàs, Àngel; Crisóstomo, Javier; Ovejas Benedicto, Victòria Júlia; Quílez Figuerola, Marcos (American Institute of Physics (AIP), 2015-10-28)
    Article
    Open Access
    We propose a method to characterize electrical resistor damage based on entropy measurements. Irreversible entropy and the rate at which it is generated are more convenient parameters than resistance for describing damage ...
  • Online cellphone battery entropy measurement for SoH estimation 

    Cuadras Tomàs, Àngel; Meinert, Florian; Büschel, Paul; Kanoun, Olfa (2016)
    Conference report
    Restricted access - publisher's policy
    The widespread use of batteries requires knowledge of their state of health (SoH). In this paper we present a method to use entropy evolution as an aging indicator for batteries. Voltage, current and temperature are ...
  • Pyroelectric conversion: harvesting energy from temperature fluctuations 

    Cuadras Tomàs, Àngel (2007-11)
    Conference report
    Open Access
  • Pyroelectric sensor for entropy measurements 

    Cuadras Tomàs, Àngel; Ovejas Benedicto, Victòria Júlia (Institute of Electrical and Electronics Engineers (IEEE), 2014)
    Conference report
    Restricted access - publisher's policy
    In this contribution we propose a system to measure entropy fluctuations in thermal systems. The system consist of a pyroelectric sensor and a temperature sensor. The pyroelectric convert thermal variations into electrical ...
  • SoH evaluation of LiFePO4 cells using impedance and thermal measurements 

    Ovejas Benedicto, Victòria Júlia; Cuadras Tomàs, Àngel; Morante Lleonart, Joan Ramon (2014)
    Conference report
    Restricted access - publisher's policy
    LiFePO4 is a promising cathode material used in Li-ion batteries. It offers better cyclability and is safer in terms of thermal runaway than previous LiCoO2 or LiMnO2 cathodes. With new applications as electric vehicles ...
  • Supercapacitor impedance in time and frequency domains 

    Cuadras Tomàs, Àngel; Ovejas Benedicto, Victòria Júlia (IEEE, 2012)
    Conference report
    Restricted access - publisher's policy
    In this contribution we estimate supercapacitor impedance from temporal measurements from two points of view: i) fitting a predefined model to the temporal data and ii) transform time domain analysis to frequency domain ...
  • Technical specifications and system architecture of a compact weather station for rice blast field study 

    Pallàs Areny, Ramon; Casas Piedrafita, Óscar; López Lapeña, Oscar; Hornero Ocaña, Gemma; Serrano Finetti, Roberto Ernesto; Quílez Figuerola, Marcos; Polo Cantero, José; Cuadras Tomàs, Àngel; PEREIRAS, Jaime; PUIGDOLLERS, Pau (2014-03-17)
    External research report
    Restricted access - confidentiality agreement
    This report describes the work carried out as part of an EC-funded project called RICE-GUARD, which is developing a novel rice blast prediction tool based on an in-field wireless sensor network. Existing systems for ...
  • Thermal energy harvesting through pyroelectricity 

    Cuadras Tomàs, Àngel; Gasulla Forner, Manuel; Ferrari, Vittorio (2010-03)
    Article
    Restricted access - publisher's policy
    Pyroelectric cells based on fabricated screen-printed PZT and commercial PVDF films are proposed as thermal energy harvesting sources in order to supply low-power autonomous sensors. The cells are electrically modelled ...